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Flow boiling augmentation
Published in Satish G. Kandlikar, Masahiro Shoji, Vijay K. Dhir, Handbook of Phase Change: Boiling and Condensation, 2019
Satish G. Kandlikar, Gian Piero Celata, Andrea Mariani
Fins provide heat transfer enhancement in single-phase flow through the increase in area associated with them. Additional surface modifications, such as louvers, are sometimes incorporated to enhance the heat transfer coefficient over the extended surfaces. Application of fins in flow boiling has been investigated by a number of investigators. Jensen (1987) presents a comprehensive summary of investigations on internal fins, including work by Lavin and Young (1965) on integral fins, Boiling et al. (1953) on longitudinal fins, and Schlunder and Chawla (1967) on star inserts. In general, the increase in heat transfer was associated with a considerably larger increase in pressure drop with such inserts. The introduction of small fins by Rifert et al. (1975) and internal spiral fins by Grachev et al. (1977) indicated the potential of such an arrangement with significantly lower pressure drop enhancement. Ito and Kimura (1979) tested a number of grooved (microfin) surfaces and showed that while heat transfer increased, the pressure drop penalty was considerably lower than large internal fins.
Applications
Published in Raj P. Chhabra, CRC Handbook of Thermal Engineering Second Edition, 2017
Joshua D. Ramsey, Ken Bell, Ramesh K. Shah, Bengt Sundén, Zan Wu, Clement Kleinstreuer, Zelin Xu, D. Ian Wilson, Graham T. Polley, John A. Pearce, Kenneth R. Diller, Jonathan W. Valvano, David W. Yarbrough, Moncef Krarti, John Zhai, Jan Kośny, Christian K. Bach, Ian H. Bell, Craig R. Bradshaw, Eckhard A. Groll, Abhinav Krishna, Orkan Kurtulus, Margaret M. Mathison, Bryce Shaffer, Bin Yang, Xinye Zhang, Davide Ziviani, Robert F. Boehm, Anthony F. Mills, Santanu Bandyopadhyay, Shankar Narasimhan, Donald L. Fenton, Raj M. Manglik, Sameer Khandekar, Mario F. Trujillo, Rolf D. Reitz, Milind A. Jog, Prabhat Kumar, K.P. Sandeep, Sanjiv Sinha, Krishna Valavala, Jun Ma, Pradeep Lall, Harold R. Jacobs, Mangesh Chaudhari, Amit Agrawal, Robert J. Moffat, Tadhg O’Donovan, Jungho Kim, S.A. Sherif, Alan T. McDonald, Arturo Pacheco-Vega, Gerardo Diaz, Mihir Sen, K.T. Yang, Martine Rueff, Evelyne Mauret, Pawel Wawrzyniak, Ireneusz Zbicinski, Mariia Sobulska, P.S. Ghoshdastidar, Naveen Tiwari, Rajappa Tadepalli, Raj Ganesh S. Pala, Desh Bandhu Singh, G. N. Tiwari
Heat transfer enhancement [or enhanced heat transfer, or for that matter enhanced mass transfer (Bergles et al., 1983; Manglik and Bergles, 2004)] refers to the study of techniques for improving the thermal performance of a heat (or mass) exchange device or system. It is sometimes also referred to as heat transfer augmentation or intensification. In general, this entails an increase in the heat transfer coefficient and encapsulates the broader science and engineering of methods for producing higher convective heat/mass transfer coefficients, reducing frictional losses, and increasing the overall thermal–hydrodynamic efficiencies of exchangers. Attempts to increase “normal” heat transfer coefficients have been recorded for more than 150 years in modern history (Bergles and Manglik, 2013) and indeed date back several thousand years in antiquity (Manglik and Jog, 2009). As a result, there is a very large store of information that has been documented and disseminated in several periodic surveys (Manglik and Bergles, 2004; Bergles and Manglik, 2013; Manglik et al., 2013). The literature comprising of technical publications, excluding patents and manufacturers’ literature, has expanded rapidly since 1955 and approximately 350–450 papers and reports on the subject are now published annually.
Heat Transfer and Pressure Drop Characteristics of Forced Convective Evaporation in Deep Spirally Fluted Tubing
Published in John C. Chen, Yasunobu Fujita, Franz Mayinger, Ralph Nelson, Convective Flow Boiling, 2019
Scott M. MacBain, Arthur E. Bergles
Research related to heat transfer enhancement continues to be an expanding field due to the ongoing interest in increasing the efficiency of heat exchanger systems. Various enhancement methods have been studied for single-phase, condensation, and boiling heat transfer. In particular, some of the enhancement techniques that have been studied for flow boiling include tubes with integral fins, twisted-tape inserts, corrugated tubes, and fluted tubes. The book by Thome (1990) discusses, in great detail, select data from the literature on several enhancements for flow boiling in tubes. In the present study, the technique to augment heat transfer is through the use of deep spiral flutes that introduce swirl into the flow, provide additional area, and present a roughness to the flow.
Heat transfer augmentation of Al2O3-Cu/water hybrid nanofluid in circular duct with inserts
Published in Cogent Engineering, 2022
Muluken Biadgelegn Wollele, Harish H.V, Mebratu Assaye
The world’s temperature is steadily rising above pre-industrial levels due to an increase in energy demand, and the release of radiation and toxic gases has resulted in extreme weather conditions (Harish Kumar et al., 2022). As a result, the use and development of several heat transfer enhancement techniques was prompted by the engineering understanding of the need to improve the thermal performance of heat exchanger in order to effect energy, cost, material, as well as a consequential mitigation of environmental degradation (Emad et al., 2017). Due to their superior qualities, research on various nanofluids for improving performance in thermal applications has attracted a lot of attention in recent years (Ahmed et al., 2012; Pehlivan et al., 2013). One of the most difficult issues that thermal engineers face is improving heat transfer in heat exchangers. As technology advances, the demand for faster and more efficient heat transfer from smaller regions or across smaller temperature differences grows. Because water, oil, and ethylene glycol mixtures lack sufficient heat transfer qualities to fulfill the increasing demand for improved heat transmission (Hamdi et al., 2019; Jiat Kendrick Wong, 2021; Moghaddami et al., 2012).
Analytical methods for the efficiency of annular fins with rectangular and hyperbolic profiles under partially wet surface conditions
Published in Numerical Heat Transfer, Part A: Applications, 2021
Worachest Pirompugd, Somchai Wongwises
Fins are extended surfaces used as a passive heat transfer enhancement technique. Fins enhance heat transfer rates by increasing surface area. Fins are applied to many heat transfer components such as heat sinks, evaporators, and condensers. For some equipment, the temperature of the fin surface is below the dew point, allowing the water vapor in the air to condense on the surface. As a result, heat and mass transfer take place along with air flow. Sometimes, the temperature of a fin is not uniform. Some areas may be under dry conditions while other areas are under wet conditions, or while the fin is under partially wet conditions. It is necessary to evaluate the efficiency of a fin to determine heat transfer. Schmidt [1] and Kan and Kraus [2] presented the efficiency of dry fins for longitudinal fins, spines, and circular fins. A number of researchers [1–7] have studied fin performance under fully dry conditions.
Experimental investigation of heat transfer and pressure drop using combination of ribs and dimples
Published in Australian Journal of Mechanical Engineering, 2023
Prakash Santosh Patil, K. K. Dhande, S. L. Borse
Heat transfer enhancement concept is observed in various applications, such as gas turbine blades, air heater of the solar system, heat exchangers, cooling of electronic instruments, etc. To get more output and efficiency, it is necessary to operate gas turbines at very high rotor inlet temperatures. These temperatures are intensely very high than melting point of the blade material; hence, turbine blades need cooling for their life and safe operation. Internal and external cooling methods are used for the gas turbine blade, and the internal cooling method involves jet impingement, rib turbulated, pin-fin, protrusions and dimples. Rib turbulators are frequently used, but this is associated with a more pressure loss.